1. Field of the Invention
The present invention relates to TDMA and SCDMA transmission systems, and more particularly, to a system and method for optimizing system performance in the presence of periodic noise.
2. Related Art
It is well known in the communications industry that noise or disturbances in a communications channel can adversely affect the performance of data communications equipment using the channel. For example, it is well known that cable modems are constrained by noise in the channel to operate at less than their full capacity. This is why cable modems do not always operate at their advertised maximum data rates. Common sources of periodic burst noise often include AC power lines, AC motors, arcing components of motors, etc. Periodic impulse noise at the 60 Hz rate, which may be produced by radiating sources such as light dimmers, vacuum cleaners, blenders, etc., adversely affects data communications equipment at the customer premises. While these impairments may not adversely affect dial-up modems to a great extent, it is believed that they significantly adversely affect high-speed modems, such as cable modems, because these types of modems utilize higher frequencies where pickup from radiating sources in the 60 Hz range may be greater.
It is desirable to be able to parameterize the periodic noise, such that the amount of information being transmitted on the physical channel is as large as possible.